Whatever file format I use them in is also how I back them up, I backup my entire desktop’s and laptop’s data to an external hard drive and an online service provider. I’m sure a compressed format would be more space efficient but that would take much more time given my use case.

In the case of my laptop it runs Linux and the filesystem I use supports “transparent compression” (almost all contents of the drive are compressed with zstd), so I’m guessing any of the ROMs on there will have already been compressed as nuch as they can (but I’m not knowledgeable enough on the file format specs)

Assuming the NAT type is one that supports peer to peer connectivity, you could try using Ethernet instead of wireless (of course this only helps when docked). This would alleviate issues with WiFi signal not being strong enough, potentially increase bandwidth, and reduce latency. Ethernet can’t improve the connection beyond the incoming connection from the ISP, it only will improve issues that stem from wireless connectivity.

I live in the countryside with my family, so maybe that’s why my Internet is so wonky?

it could very well be this, when I visit my parents in the countryside the internet is sometimes not good enough, and other times it is adequate (satellite internet, so weather can impact it).